The heat is on Omar Minaya to respond after a flurry of high-profile moves around baseball yesterday — none of them good for the Mets.

Just hours after word broke that top pitching free agent John Lackey had signed with the Red Sox, the NL East rival Phillies were putting the finishing touches on a three-way blockbuster with Toronto and Seattle that would land them former Cy Young winner Roy Halladay.

While Philadelphia had to give up fellow former Cy Young winner Cliff Lee to get Halladay, the two bold-faced developments – combined with the continued inaction from the camps of Met free-agent targets Jason Bay and catcher Bengie Molina – made for a PR nightmare for Minaya.

That’s because the Mets have made no prominent free-agent signings of their own this winter while their biggest rival arguably strengthened its rotation and their No. 1 pitching target in free agency got away without so much as a contract offer from Minaya.

The moves will intensify the tension on Minaya to counter in the wake of a 70-92 finish. That counter is likely to be adding a fifth year to Minaya’s four-year, roughly $65 million offer to Bay or joining the sweepstakes for fellow All-Star left fielder Matt Holliday if Bay spurns the Mets.

A team source said the Mets expect to hear a decision from Bay sometime this week. Molina, meanwhile, is balking at the Mets’ two-year offer in hopes they will come through with a third year guaranteed, according to a league source.

Boston’s decision to sign Lackey could mean the Red Sox are out of the running for Bay and Holliday, an indication that gained strength last night when they reportedly agreed to terms with veteran outfielder Mike Cameron, a former Met, on a two-year deal.

But Boston’s exit doesn’t necessarily make the Mets a lock to get Bay at just four years because there is reportedly is a mystery team – believed to be the Mariners or Angels – that already has given Bay a five-year proposal.

Lackey’s signing, meanwhile, caught the Mets by surprise and indicated Minaya had misread the market.

The Mets had made it clear at the Winter Meetings last week that they planned to turn to Lackey only if their offer to Bay was rejected. But that decision to wait on Lackey backfired when the 31-year-old righty jumped to Boston for a reported $85 million over five years.

With Lackey — by far the best starter available in free agency – now off the table, the Mets will now have to consider a host of less-exciting, second-tier pitchers to bolster a rotation that drops off considerably after ace Johan Santana.

Among the free-agent candidates are Joel Pineiro, Jason Marquis and Jon Garland, as well as rehabbing veterans Chien-Ming Wang, Ben Sheets and Erik Bedard. Trade possibilities include Derek Lowe of the Braves and Bronson Arroyo of the Reds.

The Mets, meanwhile, are facing heat from their fans for not pursuing Halladay, but the criticism appears misguided because they never were a realistic destination for the big right-hander.

Not only does Halladay have a full no-trade clause, but the Mets weren’t going to pillage their farm system for him and never were going to pay Halladay an average of $20 million per year for three years that he reportedly received from Philadelphia.